How to Free Convert Disk to GPT without Data Loss

When an uninitialized hard disk is connected to host computer, the first task is to create partition table. There are two forms of partition tables: GPT and MBR. The largest capacity of hard disk that MBR support is 2TB, while for GPT, the capacity soars to 18EB.
Note: 1EB=1024PB=1,048,576TB

  • About MBR
  • MBR (Master Boot Record) is the loader code in the headmost end of a hard drive, and lies in cylinder 0, head 0, sector 1. It is responsible for the operating system (DOS) to identify the legality of a partition and the location of partition boot information. MBR is generated by DOS in the initialization of the hard disk.

  • About GPT
  • GPT(GUID Partition Table) is the partition structure of a physical disk. Based on UEFI, it is developed to replace MBR in BIOS. GPT adds support for new computer hardware, among which hard disks larger than 2TB is a representative.
    Note: UEFI (Unified Extensible Firmware Interface) is a brand new type of interface standard. This interface standard is used for the operating system to automatically load from the pre-boot operating environment to operating system, so that the boot process is simplified and time-saving.

  • MBR or GPT
  • If you are puzzled by adopting GPT or MBR, these four factors may give you some inspiration.
    1. Disk capacity. MBR can only recognize a hard disk that is smaller or equal to 2TB. Disks larger than 2TB should adopt GPT style to make full use of the disk.
    2. The number of partitions. If you want to divide a disk into 5 or more partitions, use GPT, for MBR can only support four primary partitions at most. But for GPT, limitless in theory.
    3. The system of mainboard. If your mainboard is UEFI, you can adopt both GPT and MBR (most UEFI motherboards today provide strong support for legacy BIOS); however, if your mainboard is BIOS, only MBR is allowed.
    4. Compatibility. MBR has better compatibility with hard disks.
    How to Convert Disk to GPT without Data Loss

  • Use Disk Management:
  • First of all, you should delete all partitions on the disk. After that, right click the disk and choose “convert to GPT/MBR Disk”.

  • Use diskpart command:
  • Also, you can convert MBR to GPT by using “diskpart” command. Run “diskpart > list disk > select disk * > clean > convert GPT/ MBR > exit”.
    Obviously, these two methods are rather easy to carry out and require no purchase or downloading. However, the fatal defect is that both of them will wipe data totally. So you need to backup all important information on the disk before you execute either of them. Given all that, it seems you’d better find another way out.

  • Use 3rd-party software:
  • The third method is right the way that can guarantee your data safety. By using 3rd-party software, you can easily convert a MBR disk to GPT or vice versa without losing data. And today’s recommendation is MiniTool Partition Wizard Free Edition.
    MiniTool Partition Wizard Free Edition can help users to complete disk/partition conversion easily and safely even if they know nothing about how to convert MBR disk to GPT disk. Now follow the tutorial offered below to have a try.
    Step 1. Run MiniTool Partition Wizard Free Edition.
    Step 2. Right click the target disk you want to convert, and choose “Convert MBR to GPT Disk“. You can also find this feature on the left panel or by clicking the “Disk” menu on the upper part.
    Step 3. Remember to click “Apply” to execute your change.

    To sum up, there are three ways for you to convert MBR to GPT or vice versa. But to convert MBR to GPT without losing data, obviously the third method is most reliable. Now download free partition magic to better manage your hard disks and partitions.
    Tips: Visit “Convert GPT Disk to MBR Disk” to learn more.
    Note: You may get confused when you try to convert a disk that contains system partition to GPT and get the error message shown below. This is because you cannot boot system from a GPT disk under Legacy BIOS mode. On the contrary, you cannot boot system from a MBR disk based on a UEFI mode neither. Usually, it is recommended to adopt Legacy BIOS + MBR and UEFI + GPT. In addition, converting GPT to MBR also has its limitation: four primary partitions at most.

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